Better sentence-writing in 30 minutes a day - Dianna Campbell 1995

A note on spelling
Subject-verb agreement
Revising at the word level

In the next exercise, you’ll notice that sometimes a small spelling change is necessary before you add an -s or -es to a base verb. For example, with a word that ends in -y, such as fry, you change the y to i before you add -es. So fry becomes fries.

Exercise 6.2

Fill in each blank with the form of verb at right that agrees with the subject. Use the base verb or add -s or -es. Make other spelling changes where necessary.

1. the article ___________ (explain)

the articles ___________

2. one baby ___________ (cry)

all the babies ___________

3. one player ___________ (win)

four players ___________

4. the team ___________ (perform)

the teams ___________

5. the ink spots ___________ (dry)

an ink spot ___________

6. the soldiers ___________ (march)

a soldier ___________

7. the telephone ___________ (ring)

telephones ___________

8. ideas ___________ (form)

an idea ___________

9. chickens ___________ (hatch)

a chicken ___________

10. a peacemaker ___________ (pacify)

peacemakers ___________